Heat and moisture production and minimum ventilation requirements of tom turkeys during brooding-growing period

摘要

Heat and moisture production rates of Nicholas tom turkeys raised under lab-scalecommercial production settings were continually measured during a five-week brooding-growingperiod. Functions were established that relate age and body mass (BM) of the birds to their specifictotal heat production rate (THP), sensible heat production rate (SHP), moisture production rate (MP),and CO{sub}2 production rate. MP of the current study included both latent heat loss of the birds andevaporation of moisture from the litter and drinkers. Comparison of the HP and MP data from thecurrent study with those in the ASAE Standard (EP 270.5) for BM = 0.1 to 1.1 kg revealed a 4 (forBM = 0.1 kg) to 282 (for BM = 1.0 kg) higher MP and a 2 to 107 lower SHP for the currentstudy. THP from the current study was generally greater (up to 49) than that in the Standardexcept for younger birds (< 0.1 kg) whose THP was 36 less than that in the Standard. THP of theexperimental tom turkeys peaked near two weeks of age. Compared with the literature data, HP andMP characteristics of the litter-grown young turkeys more closely resemble those of equal BMbroilers raised on litter (Reece and Lott, 1982). Minimum ventilation rates (MVR) based on the newMP data for the five-week brooding-growing period were determined and tabulated for selected coldoutside conditions and thermoneutral inside conditions. There were substantial discrepancies inMVR between the literature (MWPS, 1990) recommendations and the values derived from this study,with the literature MVR being 20 to S57 of the derived MVR. The age- or BM-dependent MVRobtained from the current study provide a new, convenient reference for ventilation design andoperation of turkey brooder houses. Moreover, the equations of CO{sub}2 production rate from thisstudy provide a practical tool for estimating ventilation rates in naturally ventilated brooder facilities.The results further revealed the urgent need to systematically update the literature HP and MP datafor ventilation design of animal structures so that modern genetics, nutrition, housing systems, andmanagement schemes can be more realistically reflected.